scottishjohn

@JSHarris can you fine tune that a little and give heat requirement for say nov-march

If loss is low enough then 5" of phonelic foam around it ,or the room its in will make it as low as economically possible-- above 5" the cost outwieghs any extra insulation value

yearly problem here --they are always trying to build a nests soemewhere-in soffits --in bushes in a old dustbin I eventually went to EBAY and bought one of those wasp powder pump things --it works well --but so will @JSHarris gadget plenty of powder and on anything they stand on to crawl up the wall to get in --once they have it on their feet --they are done--same as ant powder.# Ihad one upstairs in my workshop in a storage area a few years ago --they came in through a hole inthe metal cladding ,where the old LPG pipe used to come ,but had not been blocked I thin it was more than one year --cos when i moved plies of packing to find it was the size of an armchair -- quick exit _lots of wasp killer /nest disolver purchased-hit it whilst wearing spray suit and air fed mask -- within a couple of day all gone ---

I think without it we would all make far more mistakes by not allowing for other things we have not yet thought of. my mantra is "If I didn,t t have bad luck --I would have no luck at all" or "if it can go wrong --it will" or "always lands butter side down " then when i do get some I,m happily suprised for a change . so yes I,m getting close to a terminal pessimist I wonder why i keep pushing so hard to find this plot to make my life even harder .Lol

probably me being thick ,but surely you just make ALL the roof in one go -going round the hips etc as you lay the GRP not section it -If so then that will be no problem . I have made a lot of additons in GRP to my main garage building and used grp for funny bits and nothing has ever moved in 25 years. I have a 3ft dis extraction pipe going up through it( for spray booth ) -and i used a sheet off the roof to make a mould to make up a half sheet of roof with a 3ft hole in it with an 6" upstand around the pipe this was fixed to roof with 2 lines of sealer under edges and fixed directly onto the plasticoated steel roof panels +glassed to the extraction pipe for good measure--never any sign of any leaks or movement all I can see now is some loss of resin from top surface as i did not us an UV top coat on the grp ,just a very resin rich lay up -so it was glossy -which was a mistake --but its all still there and fine. keep polyester resin away from insulation ,it will melt it-no gaps in sarking boards for it to run through use expoxy resins if you want to use it with foam -- thats was how the wing on our europa home build aircraft wing and things was made --blue foam core and west expoxy system and fancy bidirectional cloth . like making a suit

I have never been against the idea of the sunamp and wonder if there is not a way to use the water heated type to better effect ,and keep your pv gen for other things . @JSHarris do you havve the total amount of heat required for your winter heating . my thoughts are maybe a very large sunamp --charged in summer by solar thermal and used for the winter,cos its no problem getting loads of heat in the summer months ,but heat loss in big tank and cost of suitably large tank are the killers to this idea As i undestand it there is virtually NO heat los from PCM-- so ideal for long term storage -also it takes up less space than water storage ,and of course the solar thermal still does work outside the summer months ,just not as good .but cost of panels is cheaper than a huge storage tank so the question is how much heat would YOU need to store for your house . to use this as a good example of well insulted house . controlling the heat from the panels is pretty easy on pump speed alone -faster means more flow/ less temp and vice versa --which is what i did with my much simpler system to get best heat

If normal life of sunamp heating element is 2-3 years and the unit its costs over £1000 --then that does not sound like a good deal for a std type dhw system -other than it takes less physical space .still a long way to go before it could take over from std dhw system for majority of houses

think thats the sort of stuff my dad used about 70years ago --pity hes dead now or i could ask him I remember him saying best lasting colour for outside woodwork was green

a bit more accurate detail think is really needed what are the walls made out of that the semi flat grp is going join too? maybe lead flashing into brick wall onto the flatish roof -plenty of length,but also a flashing on roof below grp finished edge of it going up under the wall flashing --? plenty of overlap on everything and no flat area to puddle .

think its just same as PB --you never have it touching the floor ,cos it can suck up moisture and skirting will cover it anyway ,

I talked to a uk zinc roof supplier a couple of years ago and he stressed very much the need for a constant ventilation space under it . for a supplier to stress that on first contact was enough to put me off the system . Its expensive enough and then to have to build another sarking board roof under it --too much for me --same as you would do for a "scottish" type slate roof , but instead of costing £30-£80sqm its £150sqm for top layer I think If i really wanted roof to look like that then the insulted panel type the kinpspan and others supply would be the way you are getting up to 0.015u roof in one layer and the look you want and as phonelic is bonded to underside --no moisture problems --ever

In scotland now If you build a house with and agricutural tie --EG -- you can start a lama farm or chicken ranch ,trout farm etc providing enough ground to be considered as possibly viable -- not one field and a "good life " type then at some point in the future you can sell the house to NON agricultural person . BUT that piece of ground will never be allowed another chicken farm +house on it So gone are the days when you had to pull the house down if it became empty or only those engaged agriculture close by could inhabit it , something my mind is contemplating +will possibly be testing out with planning ,but i think alpaca,s are a better temperament than spitting,biting lamas, not sure if its now the same in england +wales --could be something to do with crofting?

used to call it "tombstone technology" in the aviation world ,or so i was assured by a man who worked for bristol after the war then finished on the concord project before retirement If the wings fall off --then we need to beef them up --sort of attitude LOL no excuse these days with computers to work all the numbers out in a split second

the £1900 would pay for an accumulator ,if you had a big pressure drop and would smooth out flow+pressure and you would still have £1k in your pocket,or just take the money and fit accumulator if needed later

yes agreed, sort of,but not in my house the one big double rad was on the back wall and window was not on that wall. so you do feel radiation of a lower temp ,eg cold ,from that area . anything above absolute zero is heat

what you are seeing there is exactly what I was eluding too in the difference between rads +ufh that I noticed with rads I never felt the cold radiation from the windows ,but very noticeable once I swopped to UFH

deifnitley Ifound this with my garage workshop -which is 25mx 24m we used to have blown air heating then changed to infrared gas tube heaters this heated the ramps the floor the mechnaics toolboxs etc --anything and everything ,which then radiated to the air .what was very noticeable was that when the big doors were opened for a car to come in the temp recovered much quickerwhen door was shut than when when blown air heating ,as all that went out of the door when it was opened I think it is the same with UFH --it heats all the furniture etc at a low level ,so opening doors does not drop temp same as with rads

I agree with you which was why i used a thermal store with my system to stop "hunting on lpg boiler +I had solar thermal input to this as well and due to house type each room has its own stat+programmer and zone valve the down side is the no one keeps all the doors shut to each room .LOL so slightly pointless -- so now its ended as basically an upstairs and downstairs zone that works fine -- and i can see with small heat store in floor you need to store it in a large tank ,which is where my idea of combined solar thermal +PV and tall large store comes in that is easy to insulate to death if you want to in the service area

with only a very slim biscuit screed then it should not be as big a problem cos you won,t be holding heat for so long or have as much of a "thermal mass" to heat up ?

maybe we should be building with strip foundations then subwalls and fill inside them with 300-400m insulation and fully floating floor on top of it with UFH built in ? no big heat store in floor then --so only heat it when you need it - temp will change very quick then and low heat losses?

thats exactly what i found

I have no calculations, just the one that matters --how much energy i have to pay for and that said 20%less with suspended floor retro fit UFH than with rads maybe that is the way then air gap and insulated suspended floor with thin screed if looking for best economy in heating costs ? or should it be same 300eps then slab ,then 100mm eps and ufh then choice of floor ? what do your numbers say to that ?

so what you are saying is is that radiators are a more effiecient system than UFH and we should all be using rads

I do not think the heat loss will be as bad as you suggest as the sort of system he is contemplating is not a "thermal store",nearly said "thermal mass", like a normal concrete slab and will change temp very quickly in comparison to a thick concrete slab -and so he will not loose as much because he is not putting it into the slab --but upwards and outwards when he needs it . I know its not a simple thing ,but i have lived with a system similar to this and it works fine and better than rads ,which is the point --it is a good half way house and as he is using gas then no need to charge up the floor at night on cheap electric ,as most do with ASHP etc and mains gas is still cheapest option for most people

I have no issue with your numbers --but that is not what the man was asking -he don,t want to rip his house to bits my physics say heats rises # its the principle that matters with rads you heat the ceiling first then the room fills downwards from the ceiling UFH heats the floor then the furniture and you,then rises to a point where it cools then drops and recirculates and so ceiling could be cooler ,dependant on height etc ,than where you are and where you need it you will note I suggested if keeping rads he insulates concrete floor to stop it sucking heat downwards anyway and even agreed that new slab would be better. and if he is doing a real up grade then maybe he should seriously consider re -boarding with 37m foam backed plasterboard--that will help a a lot with heat loss through walls and ceiling .. 50 year old house will have next to sod all wall or ceiling insulation . I know from when i did my house that it made a big difference in heat loss and noise level